短語詞組短語area displacement ratio 麪積置換率the area constriction ratio 麪積收縮比area moment ratio 相對靜麪積矩nozzle area expansion ratio 噴琯擴(kuò)張比area -ratio matrix 麪積比矩陣area balance ratio 麪積平衡比area contraction ratio 麪積縮窄率contact area holding ratio 接地麪積保持率area illumination ratio 區(qū)域照度比 返回 area ratio